1. Field of the Invention
The present invention relates to a method for transmitting and processing commands and data, and particularly, to a method for transmitting commands and data through a serial interface and processing the same.
2. Description of the Background Art
Recently, personal digital assistants (PDA) which were utilized for a business purpose in enterprises or the like are being popularized by general users. The personal digital assistant (PDA) includes various functions such as personal schedule management, an e-book, a digital music player, a game and the like.
The personal digital assistant, unlike a general computer, records an operating system (OS) and an application in a read only memory (ROM). In the conventional art, the OS and the application could not be upgraded because they were recorded in a mask ROM. However, at present, by being recorded in a Flash ROM, the OS and the application can be upgraded.
FIG. 1 is a view showing a structure of a ROM and a random access memory (RAM) of a general PDA.
As shown, the ROM of the PDA includes a bootloader region 101, an operating system and application region 102 and a system configuration data region 103. The RAM of the PDA includes a bootloader RAM region 104, a system region and a storage region 105, and an additional region 106.
First, when power is applied to the PDA, the bootloader 101 is executed.
The bootloader 101 initializes the hardware of the PDA, and passes the OA 102 a control. When the hardware is initialized, the OA 102 boots and executes the PDA.
Meanwhile, to correct a bug of the software of the PDA or to improve performance of the PDA, a method for easily upgrading and backing up the ROM of the PDA is required. Namely, the conventional art is disadvantageous in that a method for transmitting and processing commands and data, which can easily and stably upgrade and back up information recorded in the PDA, is not employed in the PDA.